Electrical transmission of vibrations



Dec. 29, 1931. 5 TU|N|NGA 1,838,886

ELECTRICAL TRANSMISSION OF VIBRATIONS Original Filed Sept. 1'7, 1929 2 Sheets-Sheet 1 U ll lll 1 O 4: 75 '25 7% In venfor Dec. 29, 1931. G. A. TUININGA 1,833,886

ELECTRICAL TRANSMISSION OF VIBRATIONS Original Filed Sept. 17, 1929 2 Sheets-Sheet 2 ro srnes 1700/0 FRE UENCY Inventor A ttorncy Patented Dec. 29, 1931 PATENT OFFICE GERALD A. TUININGA, OF EVERETT, WASHINGTON mncrmcen raansmrssron or vnmarrons Application filed 'se tember 17, 1929, Serial No. 398,258. Renewed May 2, 1931.

fragmentary top plan view of a violin equipped with the novel ap-' pliance,

Figure 2 represents a cross sectional view through the violin and showing in side elevation the novel appliance,

Figure 3 represents a diagrammatlc view of the electrical wiring.

Figure 4 is an end elevation of the electromagnetic unit of the appliance,

Figure 5 is a perspective view of the bracket for supporting one of the CO1lS.

Referring to the drawings wherein like numerals designate corresponding parts, it will be seen that numeral 5 denotes the usual sound box of a violin, but it is to be under stood that any type of musical instrument is suitable for use in conjunction with the appliance.

The bridge 6 as illustrated in Figure 2 has the strings 7 trained thereover in the usualmanner and this bridge piece has the armature bar 8 of the present invention rigidly secured thereto.

A clamp structure generally referred to by the numeral 9 serves to support the stationary portion of the appliance denoted generally by numeral 10, in the manner shown in Figure 2. The clamp structure includes an upper section 11 and a lower section 12. The lower section 12 is substantially L- shaped in elevation and has its upper end portion provided with threads 13 for engagement within the turn buckle 14.

The upper section 11 comprises a post having a laterally disposed foot 15 thereon for engagement against the top side of the sound box 5 in the manner shown, while a depending shank 16 is provided with threads 17 for I engagement within the opposite end portion of the turn buckle 14. i

A V-shaped frame 18 is secured at its apex to the upper end of the clamp section 11 that is disposed horizontally above the sound box 5. The free ends of the frame 18 are disposed 00 in parallelism as at 19 and are further bent outwardly as at 20 for engagement against the seat 21 of the U-shaped coil support 22.

A coil 23 is arranged on the bight portion of the U-shaped support 22, while the feet of 66 the same engage against adjacent end por tions of corresponding L-shaped pole pieces 23-23, which are disposed through coils 2 1-2 1. The outer ends of the pole pieces 2323 terminate beyond the coils 2424 in- 7a terposed with respect to the armature 8.

As is shown in Figure 3, the wire 25 leads to one side of one of the coils 24, while the outward side of the opposite coil has a conductor 26 leading therefrom, said conductor 26 and Wire 25 being connected to the first stage of an amplifier. The coil 23 is in the battery circuit 27 It will thus be seen that the movement of the armature 8, which is rigidly secured to the bridge piece 6, causes'changes in the field of the coils 2&24. These magnetic changes cause electrical currents to flow in the coil circuits which are led to the first stage of the amplifier.

The electric currentflows first in one direc tion and then in the other, varying in unison with the movement of the armature. The advantage of using this style of transmitter is that no other electric current caused by foreign sound or vibration can in any way enter into the circuit.

By using this transmitter with amplifying apparatus, three or four stages of audio-frequency amplification with proper equipment and loud speakers, the natural tone of the in strument can be increased in volume to any degree of loudness.

While the foregoing description has been set forth in specific terms it is to be understood that numerous changes in the specific shape, size, materials may be resorted to Without departing from the spirit or scope of the invention as claimed hereinafter.

Having thus described my invention, What I claim as new is:

An electric transmitter for musical instruments comprising an armature element for attachment to the vibratory part of the instrument, electro-magnetic means adapted to be affected by the armature for setting up an impulsing current, and means for supporting the said magnetic means, said support comprising a pair of sections, a turn buckle for connecting the said sections together and in clamping engagement With the musical instrument, a post on one of the sections, said post being connected to the magnetic means for supporting the same in spaced relation to the vibratory area of the instrument.

In testimony whereof I aflix my signature.

GERALD A. TUININGA. 

